package opam-core

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Sets with extended interface and infix operators

include Set.S
type elt

The type of the set elements.

type t

The type of sets.

val empty : t

The empty set.

val is_empty : t -> bool

Test whether a set is empty or not.

val mem : elt -> t -> bool

mem x s tests whether x belongs to the set s.

val add : elt -> t -> t

add x s returns a set containing all elements of s, plus x. If x was already in s, s is returned unchanged (the result of the function is then physically equal to s).

  • before 4.03

    Physical equality was not ensured.

val singleton : elt -> t

singleton x returns the one-element set containing only x.

val remove : elt -> t -> t

remove x s returns a set containing all elements of s, except x. If x was not in s, s is returned unchanged (the result of the function is then physically equal to s).

  • before 4.03

    Physical equality was not ensured.

val union : t -> t -> t

Set union.

val inter : t -> t -> t

Set intersection.

val diff : t -> t -> t

Set difference.

val compare : t -> t -> int

Total ordering between sets. Can be used as the ordering function for doing sets of sets.

val equal : t -> t -> bool

equal s1 s2 tests whether the sets s1 and s2 are equal, that is, contain equal elements.

val subset : t -> t -> bool

subset s1 s2 tests whether the set s1 is a subset of the set s2.

val iter : (elt -> unit) -> t -> unit

iter f s applies f in turn to all elements of s. The elements of s are presented to f in increasing order with respect to the ordering over the type of the elements.

val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a

fold f s a computes (f xN ... (f x2 (f x1 a))...), where x1 ... xN are the elements of s, in increasing order.

val for_all : (elt -> bool) -> t -> bool

for_all p s checks if all elements of the set satisfy the predicate p.

val exists : (elt -> bool) -> t -> bool

exists p s checks if at least one element of the set satisfies the predicate p.

val filter : (elt -> bool) -> t -> t

filter p s returns the set of all elements in s that satisfy predicate p. If p satisfies every element in s, s is returned unchanged (the result of the function is then physically equal to s).

  • before 4.03

    Physical equality was not ensured.

val partition : (elt -> bool) -> t -> t * t

partition p s returns a pair of sets (s1, s2), where s1 is the set of all the elements of s that satisfy the predicate p, and s2 is the set of all the elements of s that do not satisfy p.

val cardinal : t -> int

Return the number of elements of a set.

val elements : t -> elt list

Return the list of all elements of the given set. The returned list is sorted in increasing order with respect to the ordering Ord.compare, where Ord is the argument given to Set.Make.

val min_elt : t -> elt

Return the smallest element of the given set (with respect to the Ord.compare ordering), or raise Not_found if the set is empty.

val min_elt_opt : t -> elt option

Return the smallest element of the given set (with respect to the Ord.compare ordering), or None if the set is empty.

  • since 4.05
val max_elt : t -> elt

Same as Set.S.min_elt, but returns the largest element of the given set.

val max_elt_opt : t -> elt option

Same as Set.S.min_elt_opt, but returns the largest element of the given set.

  • since 4.05
val choose : t -> elt

Return one element of the given set, or raise Not_found if the set is empty. Which element is chosen is unspecified, but equal elements will be chosen for equal sets.

val split : elt -> t -> t * bool * t

split x s returns a triple (l, present, r), where l is the set of elements of s that are strictly less than x; r is the set of elements of s that are strictly greater than x; present is false if s contains no element equal to x, or true if s contains an element equal to x.

val find_first : (elt -> bool) -> t -> elt

find_first f s, where f is a monotonically increasing function, returns the lowest element e of s such that f e, or raises Not_found if no such element exists.

For example, find_first (fun e -> Ord.compare e x >= 0) s will return the first element e of s where Ord.compare e x >= 0 (intuitively: e >= x), or raise Not_found if x is greater than any element of s.

  • since 4.05
val find_first_opt : (elt -> bool) -> t -> elt option

find_first_opt f s, where f is a monotonically increasing function, returns an option containing the lowest element e of s such that f e, or None if no such element exists.

  • since 4.05
val find_last : (elt -> bool) -> t -> elt

find_last f s, where f is a monotonically decreasing function, returns the highest element e of s such that f e, or raises Not_found if no such element exists.

  • since 4.05
val find_last_opt : (elt -> bool) -> t -> elt option

find_last_opt f s, where f is a monotonically decreasing function, returns an option containing the highest element e of s such that f e, or None if no such element exists.

  • since 4.05
Iterators
val to_seq_from : elt -> t -> elt Seq.t

to_seq_from x s iterates on a subset of the elements of s in ascending order, from x or above.

  • since 4.07
val to_seq : t -> elt Seq.t

Iterate on the whole set, in ascending order

  • since 4.07
val add_seq : elt Seq.t -> t -> t

Add the given elements to the set, in order.

  • since 4.07
val of_seq : elt Seq.t -> t

Build a set from the given bindings

  • since 4.07
val map : (elt -> elt) -> t -> t
val is_singleton : t -> bool
val choose_one : t -> elt

Returns one element, assuming the set is a singleton. Raises Not_found on an empty set, Failure on a non-singleton.

val choose_opt : t -> elt option
val of_list : elt list -> t
val to_string : t -> string
val to_json : t -> OpamJson.t
val of_json : OpamJson.t -> t option
val find : (elt -> bool) -> t -> elt
val find_opt : (elt -> bool) -> t -> elt option
val safe_add : elt -> t -> t

Raises Failure in case the element is already present

val fixpoint : (elt -> t) -> t -> t

Accumulates the resulting sets of a function of elements until a fixpoint is reached

val map_reduce : ?default:'a -> (elt -> 'a) -> ('a -> 'a -> 'a) -> t -> 'a

map_reduce f op t applies f to every element of t and combines the results using associative operator op. Raises Invalid_argument on an empty set, or returns default if it is defined.

module Op : sig ... end
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